Four months ago on a bright but windy day in early August, seventeen passengers and three crew lost their lives when 1935-vintage Junkers Ju-52/3m HB-HOT made an almost vertical high speed dive into Piz Segnas, a 2,540m high mountain pass in Switzerland. The aircraft had been operating a Ju-Air pleasure flight and was en route from Locarno to its base at Dubendorf near Zurich. As many as four of these elegant old ladies of the air have been operated by the firm since they were retired by the Swiss Air Force in the early 1980s, and this is the first time they have been involved in such a tragedy.
A few days ago the Swiss TSB (Transportation Inspection Safety Board) published an interim report. It revealed that it had not found any evidence that a serious technical failure caused the accident. However, severe structural damage including cracks and corrosion of the main spar was found in areas that it would have been impossible to inspect during normal maintenance activities. Furthermore, questions were raised about how repairs were made to an engine mount, and incomplete documentation for some spare parts and hangar tasks. Those findings are rather disturbing and inevitably raise questions about the use of other very old aircraft to transport paying passengers, even if only on pleasure flights.
The wreckage of HB-HOT (Swiss TSB)
Sadly this isn't the first time an 'old' aircraft has crashed during a pleasure flight. Just over 20 years ago on September 26, 1996 Dutch Dakota Association Douglas DC-3 PH-DDA was lost near Den Oever and 26 passengers and six crew lost their lives. Eight years ago a similar aircraft flown by Air Service Berlin made a forced landing and was written off - thankfully without loss of life. Many thousands of passengers are transported without incident on similar operations every year, conducted by highly reputable organisations including a few major airlines. The Aviation Oracle has travelled in a number of aircraft many would regard as 'suspect': a Douglas DC-3 in Bolivia with no seats and a main door secured by a broom handle; a Curtiss C-46 with engines that leaked oil, took 15 minutes to start, and had a huge crack in the wind shield; and in a Cessna 208 Caravan when the pilot thought that the correct take-off technique was to hurtle down the runway with the nose raised and the stall warner buzzing. Nevertheless I have never felt really uncomfortable or in any danger during any of the 2,500 or more flights I have taken over the last 45 years. Although the two remaining Ju-Air Ju-52s have again been grounded for inspections following the release of the interim report on HB-HOT, I would have no qualms about riding in them when they go back into service.
Heritage aircraft, by their very nature, cannot be certified to the same lofty standards we enjoy today with every major airline. The time between failure for some of the major components will probably be lower than current standards, just as they might be with a vintage car. Sophisticated systems such as slides will probably be not fitted. However, this doesn't mean they are inherently unsafe. As long as they are maintained to the highest standards and flown within their limitations with a mind to their idiosyncrasies they are more than capable of continuing to provide enjoyment to the passengers who travel in them every year. The loss of life in the Swiss accident is truly tragic and there may well be lessons to be learned. But The Aviation Oracle hopes it doesn't result in the permanent grounding of historic flying machines or a ban on them carrying passengers. The loss of HB-HOT is still under investigation and a final report will be issued in due course.
Text © The Aviation Oracle